The invention relates to a radiator arrangement of the type having a fan with a variable fan drive, at least one heat exchanger arranged in front of the fan for exchanging heat between engine coolant and air taken in by the fan, a temperature sensor for the engine coolant, and an electric control device which controls the fan drive as a function of the temperature sensed by the temperature sensor.
Radiator arrangements of this type are known (DE-37 14 842 Al-P 80 01). In the known constructions, the electric control device, which is part of the vehicle, is always connected with the heat exchanger and the fan drive subsequently, the corresponding temperature sensors also not being installed before the control device is connected. In the case of vehicles which are equipped with a radiator arrangement of the type referred to above, the control device is generally located in an area situated outside the engine compartment, such as the driver's cab. In constructions of this type, it is therefore a disadvantage that the coordination of the desired control characteristics and the adjusting of the control device required for this purpose and possibly of other existing components of the control system can only be carried out at the customer's after the installation of the radiator. This is relatively expensive and, more importantly, does not always result in the adjustment of the desired control characteristics of the radiator.
An object of the invention is to develop a radiator arrangement of the initially mentioned type in such a manner that also the future operating method of the radiator can also be determined by the radiator manufacturer. For achieving this object, the radiator arrangement is constructed with the heat exchanger and fan combined as a structural unit, wherein the electric control device and the temperature sensor and associated connecting lines are fastened directly to the structural unit. By means of this development, the control device with all its connecting lines and temperature sensors becomes part of the structural unit which can be preassembled and which comprises the fan and the heat exchanger. Therefore, the whole radiator arrangement can be adjusted before its delivery. The only measure that is still required is the electrical connection of the control device or its connection with additional sensors which, however, can be achieved in a simple manner and advantageously with respect to the assembling by means of the arrangement of plug elements.
Advantageous further developments are provided in preferred embodiments of the invention, including deposition of the temperature sensor directly at the housing for the control device, which housing is threadably attachable in an opening in the radiator tank of the heat exchanger. This arrangement provides the advantage that no connecting lines exist between the control device and the temperature sensor assigned to the cooling circulating system of the heat exchanger which may be subjected to outside influences. The control device and the temperature sensor constitute a structural unit which can be screwed in and which, in a simple manner, by means of connecting cables, may lead to additional signal generators and to the power connection.
In especially preferred embodiments, the preassembled radiator arrangement can also be used for the control of the cooling water temperature as well as for the control of other quantities, such as the air temperature of the charge air. For this purpose, the control device can implement corresponding characteristic curves for water and air temperatures. Finally, the advantage is also achieved in certain preferred embodiments, of the direct and determinable assignment of the rotational fan speed to certain cooling water temperatures or outside temperatures with the rotational speed of the fan monitored directly. A relatively expensive control device can therefore be integrated originally into the structural radiator unit. This radiator unit can be laid out correspondingly at the manufacturer's so that during the assembly, a cumbersome adjustment of the control system becomes superfluous.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.